Connecting assembly between a shaft journal and a constant velocity universal joint with threaded sleeve

ABSTRACT

A connecting assembly between a shaft journal which is axially secured, and a constant velocity universal joint whose inner joint part is engaged by the shaft journal in a rotationally fast way, wherein there is provided a threaded sleeve which is held so as to be axially secured and freely rotatable relative to the inner joint part and which comprises a thread which can be threaded on to a counter thread on the shaft journal.

TECHNICAL FIELD

The invention relates to a connecting assembly between a shaft journalwhich is supported directly and a constant velocity universal jointwhose inner joint part is rotationally securedly engaged by the shaftjournal, more particularly used in the propeller shaft of a motorvehicle drive. The shaft journal can be axially and radially secured ina manual gearbox or in an axle drive, with the constant velocityuniversal joint then being located at one end of the propeller shaft.The shaft journal can also be radially resiliently suspended in anresilient intermediate bearing, with the constant velocity universaljoint then being used as a central bearing of a two-part propellershaft.

BACKGROUND

The installation space of motor vehicles is subjected to greater andgreater restrictions. This also applies to the installation space forthe driveline. At the same time, more stringent requirements have to bemet by the mounted driveline as far as reliable residual out-of-balanceis concerned.

In the case of present-day solutions, the rear propeller shaft joint isconnected to the axle drive input journal via a flange connection, andit has to be accepted that the tolerances of the flange runout (inrespect of the shaft journal axis), of the joint runout and thejoint/flange fit are added up, a particular problem being the axialfixing of the joint relative to the shaft journal.

From WO 98/35174 it is known to connect the outer joint part of the rearpropeller shaft joint directly via splines to the input journal of theaxle drive.

SUMMARY OF THE INVENTION

The present invention to provide a connecting assembly of the initiallydefined type wherein it is possible to achieve a connection by means ofsecure axial fixing means in a simple way, more particularly involving asimple assembling procedure.

A first solution is characterised by a threaded sleeve which is held soas to be axially secured and freely rotatable relative to the innerjoint part and which comprises a thread which is threaded on to acounter thread on the shaft journal. It is proposed that the thread ofthe threaded sleeve is an inner thread and the counter thread at theshaft journal is an outer thread. It is also proposed that an outerthread at the shaft journal carries a nut against which the threadedsleeve is made to stop and is secured against rotation. Theanti-rotation effect can be achieved by prick punch or by other priorart means.

According to a first embodiment, the threaded sleeve is connected to theinner joint part and, more particularly, engages a recess in the innerjoint part, in which recess there is arranged an axial securingmechanism. The connection between the threaded sleeve and the innerjoint part can be achieved by a securing ring.

According to a second embodiment, the threaded sleeve is directlyconnected to an intermediate sleeve which is welded to the inner jointpart and, more particularly, extends over the intermediate sleeve bymeans of a recess in which there is formed an axial securing mechanism.

The above-mentioned nut on the shaft journal more particularly serves toclamp the rolling-contact bearing on the shaft journal.

A second solution is characterised by a threaded sleeve which is axiallysecured and arranged so as to be freely rotatable relative to the shaftjournal and comprises a thread which, via a counter thread, can be atleast indirectly threaded to the inner joint part. More particularly,the freely rotatable connection can be achieved between the threadedsleeve and a nut threaded on to the shaft journal, wherein the threadedsleeve, more particularly, engages a recess in the nut in which theaxial securing mechanism is arranged. The threaded connection betweenthe threaded sleeve and the inner joint part can be achieved indirectlyvia a projecting sleeve connected to the inner joint part or directlyvia a projecting sleeve integrally formed on to the inner joint part.More particularly, the threaded sleeve is an outer thread and thecounter thread at the inner joint part an inner thread which is providedin a projecting sleeve which is attached to the inner joint part. Thethreaded sleeve is made to abut against the attachable sleeve or againstthe inner joint part while being rotationally secured. In this case,too, said nut on the shaft journal can simultaneously serve to clamp arolling contact bearing on the shaft journal.

For both solutions, for axially freely securing the threaded sleeverelative to the inner joint part and, respectively, to the shaftjournal, there is provided a securing ring engaging correspondingannular grooves. The annular grooves are preferably provided on thethreaded sleeve on the one hand and on the inner joint part or on theattachable sleeve and the nut respectively on the other hand.

According to a particularly advantageous embodiment which, to a largeextent, permits the grease-filled, sealed constant velocity joint to bepre-assembled, a seal, at its outer circumference, is at leastindirectly sealingly and rotationally securedly connected to the outerjoint part of the constant velocity universal joint, which seal, at itsinner circumference, sealingly rests on the threaded sleeve, theintermediate sleeve or the projecting sleeve.

For this purpose, at the end of the inner joint part, which end isopposed to the seal and points to the propeller shaft tube, there isattached a further cover which sealingly closes the aperture of theinner splines of the inner joint part. The propeller shaft tube itselfis connected to the outer joint part of the constant velocity universaljoint.

The inventive connecting assembly has the following advantages:

-   -   the constant velocity universal joint, the sealing mechanism and        the axial securing mechanism form one unit;    -   the assembly can be released in a non-destructive way and can be        repeatedly closed; it can be released and re-closed at most        while destroying and replacing the securing ring;    -   the constant velocity universal joint and the axial securing        mechanism can be provided in the form of a grease-filled, sealed        unit without having to provide any additional transport sealing        means;    -   said unit can be mounted very easily on the shaft journal;    -   simple modifications allow a corrosion protection for the        adjoining technical parts, more particularly, for the thread of        a clamping nut for clamping the shaft journal bearing;    -   the inventive connecting assembly is largely independent of the        type of joint used.

The inventive connection between the inner joint part and the shaftjournal via splines comprises only one single toleranced connection. Theposition of the rotational axis of the propeller shaft can be fixed muchmore accurately. Any out-of-balance resulting from the eccentricity ofmounting the joint is avoided.

Preferred embodiments of the invention are illustrated in the drawingsand will be described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first embodiment of an inventive connecting assemblyhaving a threaded sleeve which is rotatable relative to the inner jointpart.

FIG. 2 shows a second embodiment of an inventive connecting assemblywhose threaded sleeve is rotatable relative to the shaft journal.

FIG. 3 shows a first embodiment of an inventive connecting assemblyhaving a threaded sleeve which is rotatable relative to the shaftjournal.

FIG. 4 shows a second embodiment of an inventive connecting assemblywhose threaded sleeve is rotatable relative to the shaft journal.

DETAILED DESCRIPTION OF THE DRAWINGS

Initially, the Figures will be described jointly to the extent that theycan be seen to comprise details corresponding to one another. A shaftjournal 11 is connected to a constant velocity universal joint 12 in theform of a counter track fixed joint in a way yet to be described ingreater detail. The shaft journal is axially and radially supported by arolling contact bearing 13 in a drive housing 14. The rolling contactbearing is axially clamped in by a nut 17 which, via its inner thread18, is threaded onto a threaded portion 36 of the shaft journal 11. Thenut 17 comprises key engagement means 19. The nut 17 is sealed via ashaft seal 20 relative to the axle drive housing 14, which nut isprotected against being damaged by a protective cap 21. The constantvelocity universal joint comprises an outer joint part 22, an innerjoint part 24, torque transmitting balls 26 and a ball cage 23. Theballs are held in first outer ball tracks 27 and in first inner balltracks 28 which open towards the housing 14 and are held in second outerball tracks 29 and second inner ball tracks 30 which open towards theopposite end.

A hollow shaft 15 is welded to the outer joint part 22, with a cover 31being inserted between the end of the hollow shaft 15 and the outerjoint part 22. At the end opposed to the drive housing 14, there iswelded a further cover to the inner joint part 24. The inner joint part24 is positioned in inner splines 34 on a splined portion 37 of theshaft journal 11.

In FIG. 1, the mechanism for axially securing the inner joint part 24,and thus the entire constant velocity universal joint 12 with theadjoining hollow shaft, 15 relative to the shaft journal 11 comprises athreaded sleeve 41′ which, by means of its inner thread 42, is threadedon to the threaded portion 36 of the shaft journal 11 until it stopsagainst the nut 17. The threaded sleeve 41 comprises circumferentiallydistributed key engagement means 43. Between the nut 17 and the threadedsleeve 41 there is inserted an O-ring seal 49. Furthermore, the threadedsleeve 41 comprises a sleeve projection 48 which is freely rotatablerelative to the shaft splines 37 and which is inserted into an innerrecess 44 in the inner joint part 24. Between the sleeve projection 43and the recess 44 there is provided a securing ring 45 which engagesmatching annular grooves 46, 47 and which secures the threaded sleeve 41in an axially fixed but rotatable way relative to the inner joint part24. A membrane seal 33 arranged in an outwardly sealing way on thethreaded sleeve 41 is secured to the outer joint part 22 by means of aplate metal sleeve 32. The unit consisting of the constant velocityuniversal joint 12 and the welded-on hollow shaft 15 can be pre-mounted,including the threaded sleeve 41 and the membrane seal 33; the universaljoint is already filled with grease and does not require any furthersealing means for transport purposes.

The described unit consisting of the constant velocity universal joint12 and the threaded sleeve 41 can be axially slid on to the splines ends37 of the shaft journal 11 without said sliding movement beingobstructed by the threaded sleeve 41. The shaft splines 37 engage theinner splines 34 at the inner joint part 24. The axial securingmechanism between the shaft journal 11 and the constant velocity joint12 are then put into effect by threading the inner thread 42 of thethreaded sleeve 41 on to the threaded portion 36 of the shaft journal11. After the threaded sleeve 41 has stopped against the nut 17, thethreaded sleeve is rotationally secured, as this has already been putinto effect for the nut 17 after the pretension for the rolling contactbearing 13 has been set.

According to a different type of mounting procedure, it is also possibleto thread the threaded sleeve 41 on to the threaded portion 36 prior toassembling the constant velocity universal joint 12 and to achieve theaxial fixing between the threaded sleeve and the inner joint part 24 bymeans of the securing ring 45 when sliding the inner joint part 24 on tothe shaft splines 37.

In FIG. 2, the mechanism for axially securing the inner joint part 24,and thus the entire constant velocity universal joint 12 with theadjoining hollow shaft 15, relative to the shaft journal 11, comprises athreaded sleeve 41′ which, by means of its inner thread 42, is threadedon to the threaded portion 36 of the shaft journal 11 until it stopsagainst the nut 17. The threaded sleeve 41′ comprises an inner recess44′ which is engaged by an intermediate sleeve 39 which is connected tothe inner joint part by a weld 40. The intermediate sleeve 39 can alsoengage the shaft splines 37. Between the intermediate sleeve 39 and therecess 34′ there is provided a securing ring 45 which engages matchingannular grooves 46, 47 and secures the threaded sleeve 41′ in an axiallyfixed, but rotatable way relative to the inner joint part 24. A membraneseal 33 which is outwardly sealingly arranged on the intermediate sleeve39 is secured to the outer joint part 22 by means of a plate metalsleeve 32. The unit consisting of the constant velocity joint 12 and thewelded-on hollow shaft 15 can be pre-assembled, including the threadedsleeve 41 and the membrane seal 33, and the universal joint can alreadybe filled with grease.

The described unit consisting of the constant velocity joint 12, theintermediate sleeve 39 and the threaded sleeve 41′ can be slid on to thesplines ends 37 of the shaft journal 11 without the axial slidingprocess being obstructed by the threaded sleeve 41′. The axial securingmechanism between the shaft journal 11 and the constant velocity joint12 are then put into effect by threading the inner thread 42 of thethreaded sleeve 41′ on to the threaded portion 36 of the shaft journal11. After the threaded sleeve 41′ has stopped against the nut 17, thethreaded sleeve is rotationally secured as this has already been putinto effect for the nut 17 after the pretension for the rolling contactbearing 13 has been set.

According to a different type of mounting procedure, it is also possibleto thread the threaded sleeve 41′ on to the threaded portion 36 of theshaft journal 11 prior to assembling the constant velocity universaljoint 12 and to achieve the axial fixing between the threaded sleeve 41′and the intermediate sleeve 39 by means of the securing ring 45 whensliding the inner joint part 24 on to the shaft splines teeth 37.

In FIGS. 3 and 4, the axial connection between the shaft journal 11 andthe constant velocity universal joint 12 is essentially effected by thethreaded sleeve 51 which engages a recess 54 in the nut 17. The threadedsleeve 51 and the nut 17 are connected to one another via a securingring 55 so as to be axially fixed but rotatable relative to one another,which securing ring engages matching annular grooves 56, 57 in thethreaded sleeve 51 and the recess 54. Furthermore, the threaded sleeve,by means of an outer thread 52, engages an inner thread 62 in theprojecting sleeve 61 which is welded to the inner joint part 24 of theconstant velocity joint 12. A membrane seal 33 which is outwardlysealingly arranged on the projecting sleeve 61 is secured to the outerjoint part 22 by means of a plate metal sleeve 32. The pre-assembledunit consisting of the constant velocity joint 12 and the hollow shaft15 with the seal 33 can also be completely assembled, filled with greaseand sealed in order, then, to be connected to the shaft journal 11. Asdescribed above, the threaded sleeve 51 has already been axially fixedto the nut 17 by means of a securing ring 55. When sliding the innersplines 34 of the inner joint part 24 on to the shaft splines 37 of theshaft journal 11, the threaded sleeve 51, by means of its outer thread,is threaded into the inner thread 62 of the projecting sleeve 61 untilthe threaded sleeve 51 axially stops against the projecting sleeve 61.Thereafter, the two sleeves 51, 61 are rotationally secured relative toone another by local plastic deformation.

According to a different type of mounting procedure, it is also possibleto thread the threaded sleeve 51 into the projecting sleeve 61 prior toassembly and to achieve the axial fixing between the threaded sleeve 51and the nut 17 by means of the securing ring 55 when sliding the innerjoint part 24 on to the shaft splines 37.

Whereas, in FIG. 3, the projecting sleeve 61 has already been partiallyinserted into the inner joint part 24 and then welded thereto, in FIG. 4the projecting sleeve 61′ and the inner joint part 24 abut one another.

1. A connecting assembly comprising: a shaft journal having a firstportion and a second, outer threaded portion, an outer joint part havingouter ball tracks, an inner joint part having inner ball tracks andhaving a bore in which the first portion of the shaft journal isdirectly engaged in a rotationally fixed way for transmitting torque,torque transmitting balls being held within the outer ball tracks of theouter joint part and the inner ball tracks of the inner joint part suchas to transmit torque between the outer joint part and the inner jointpart, a nut which is threaded on to said outer thread of said shaftjournal; and a threaded sleeve being axially secured to said nut andbeing freely rotatable relative to said nut and said shaft journal, andfurther comprising a thread which cooperates with a counter thread ofthe inner joint part or of a projecting sleeve extending from the innerjoint part so as to at least indirectly thread the threaded sleeve tothe inner joint part such that the threaded sleeve and nut axially fixthe shaft journal relative to the inner joint part.
 2. An assemblyaccording to claim 1 wherein the threaded sleeve engages a recess in thenut.
 3. An assembly according to claim 1, wherein the thread is an outerthread and the counter thread at the inner joint part is an inner threadwhich is provided in a projecting sleeve which is fixed to the innerjoint part.
 4. An assembly according to claim 3, wherein the threadedsleeve abuts against the projecting sleeve and is rotationally securedthereon.
 5. An assembly according to claim 3 comprising a seal which, byits outer circumference, is at least indirectly sealingly connected tothe outer joint part of the constant velocity universal joint and isrotationally secured thereon, and the seal, by its inner circumference,is sealingly positioned on the projecting sleeve.
 6. An assemblyaccording to claim 1, wherein a radial face of the threaded sleeve abutsagainst an end face of the inner joint part and is rotationally securedthereon.
 7. An assembly according to claim 1, wherein the threadedsleeve is axially secured to the nut by a securing ring engagingcorresponding annular grooves.